1. Field of the Disclosure
The present disclosure relates to a wavelength and bandwidth allocation method in WDM/TDM-PON.
2. Discussion of the Background Art
Large-capacity access service is required with the rapid spread of internet. PON (Passive Optical Network) as an optical transmission system of a shared access system in which a transmission bandwidth of a line is shared by a plurality of users is realized, and reduction in cost of an apparatus is advanced, whereby FTTH (Fiber To The Home) service is provided at a realistic price.
By virtue of the realization of the PON, the telecommunications market is continued to be developed; however, the communication capacity of the PON is required to be increased to meet further service requirements of users. However, in PON network, an optical signal used in an uplink signal has a single wavelength, and therefore, when the number of subscribers using the PON network simultaneously increases, the time allocated to one subscriber is reduced, so that there is a problem that the transmission rate is deteriorated. In order to solve this problem, there has been proposed a wavelength variable type WDM/TDM-PON as a network system in which expandability of a total bandwidth is given to PON (TDM-PON) by using another multiplexing technique (WDM) (Patent Literature 1).